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![Martin KaFai Lau](/assets/img/avatar_default.png)
Right now, skb->tstamp is reset to 0 whenever the skb is forwarded. If skb->tstamp has the mono delivery_time, clearing it can hurt the performance when it finally transmits out to fq@phy-dev. The earlier patch added a skb->mono_delivery_time bit to flag the skb->tstamp carrying the mono delivery_time. This patch adds skb_clear_tstamp() helper which keeps the mono delivery_time and clears everything else. The delivery_time clearing will be postponed until the stack knows the skb will be delivered locally. It will be done in a latter patch. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
343 lines
7.8 KiB
C
343 lines
7.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Forwarding decision
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* Linux ethernet bridge
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*
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* Authors:
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* Lennert Buytenhek <buytenh@gnu.org>
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*/
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#include <linux/err.h>
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#include <linux/slab.h>
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#include <linux/kernel.h>
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#include <linux/netdevice.h>
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#include <linux/netpoll.h>
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#include <linux/skbuff.h>
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#include <linux/if_vlan.h>
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#include <linux/netfilter_bridge.h>
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#include "br_private.h"
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/* Don't forward packets to originating port or forwarding disabled */
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static inline int should_deliver(const struct net_bridge_port *p,
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const struct sk_buff *skb)
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{
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struct net_bridge_vlan_group *vg;
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vg = nbp_vlan_group_rcu(p);
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return ((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) &&
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p->state == BR_STATE_FORWARDING && br_allowed_egress(vg, skb) &&
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nbp_switchdev_allowed_egress(p, skb) &&
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!br_skb_isolated(p, skb);
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}
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int br_dev_queue_push_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
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{
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skb_push(skb, ETH_HLEN);
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if (!is_skb_forwardable(skb->dev, skb))
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goto drop;
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br_drop_fake_rtable(skb);
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if (skb->ip_summed == CHECKSUM_PARTIAL &&
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eth_type_vlan(skb->protocol)) {
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int depth;
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if (!__vlan_get_protocol(skb, skb->protocol, &depth))
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goto drop;
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skb_set_network_header(skb, depth);
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}
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br_switchdev_frame_set_offload_fwd_mark(skb);
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dev_queue_xmit(skb);
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return 0;
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drop:
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kfree_skb(skb);
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return 0;
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}
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EXPORT_SYMBOL_GPL(br_dev_queue_push_xmit);
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int br_forward_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
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{
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skb_clear_tstamp(skb);
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return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING,
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net, sk, skb, NULL, skb->dev,
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br_dev_queue_push_xmit);
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}
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EXPORT_SYMBOL_GPL(br_forward_finish);
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static void __br_forward(const struct net_bridge_port *to,
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struct sk_buff *skb, bool local_orig)
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{
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struct net_bridge_vlan_group *vg;
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struct net_device *indev;
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struct net *net;
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int br_hook;
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/* Mark the skb for forwarding offload early so that br_handle_vlan()
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* can know whether to pop the VLAN header on egress or keep it.
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*/
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nbp_switchdev_frame_mark_tx_fwd_offload(to, skb);
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vg = nbp_vlan_group_rcu(to);
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skb = br_handle_vlan(to->br, to, vg, skb);
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if (!skb)
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return;
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indev = skb->dev;
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skb->dev = to->dev;
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if (!local_orig) {
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if (skb_warn_if_lro(skb)) {
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kfree_skb(skb);
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return;
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}
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br_hook = NF_BR_FORWARD;
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skb_forward_csum(skb);
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net = dev_net(indev);
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} else {
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if (unlikely(netpoll_tx_running(to->br->dev))) {
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skb_push(skb, ETH_HLEN);
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if (!is_skb_forwardable(skb->dev, skb))
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kfree_skb(skb);
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else
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br_netpoll_send_skb(to, skb);
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return;
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}
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br_hook = NF_BR_LOCAL_OUT;
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net = dev_net(skb->dev);
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indev = NULL;
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}
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NF_HOOK(NFPROTO_BRIDGE, br_hook,
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net, NULL, skb, indev, skb->dev,
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br_forward_finish);
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}
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static int deliver_clone(const struct net_bridge_port *prev,
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struct sk_buff *skb, bool local_orig)
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{
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struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
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skb = skb_clone(skb, GFP_ATOMIC);
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if (!skb) {
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dev->stats.tx_dropped++;
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return -ENOMEM;
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}
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__br_forward(prev, skb, local_orig);
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return 0;
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}
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/**
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* br_forward - forward a packet to a specific port
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* @to: destination port
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* @skb: packet being forwarded
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* @local_rcv: packet will be received locally after forwarding
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* @local_orig: packet is locally originated
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*
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* Should be called with rcu_read_lock.
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*/
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void br_forward(const struct net_bridge_port *to,
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struct sk_buff *skb, bool local_rcv, bool local_orig)
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{
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if (unlikely(!to))
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goto out;
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/* redirect to backup link if the destination port is down */
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if (rcu_access_pointer(to->backup_port) && !netif_carrier_ok(to->dev)) {
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struct net_bridge_port *backup_port;
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backup_port = rcu_dereference(to->backup_port);
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if (unlikely(!backup_port))
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goto out;
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to = backup_port;
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}
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if (should_deliver(to, skb)) {
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if (local_rcv)
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deliver_clone(to, skb, local_orig);
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else
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__br_forward(to, skb, local_orig);
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return;
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}
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out:
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if (!local_rcv)
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kfree_skb(skb);
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}
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EXPORT_SYMBOL_GPL(br_forward);
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static struct net_bridge_port *maybe_deliver(
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struct net_bridge_port *prev, struct net_bridge_port *p,
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struct sk_buff *skb, bool local_orig)
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{
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u8 igmp_type = br_multicast_igmp_type(skb);
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int err;
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if (!should_deliver(p, skb))
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return prev;
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nbp_switchdev_frame_mark_tx_fwd_to_hwdom(p, skb);
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if (!prev)
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goto out;
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err = deliver_clone(prev, skb, local_orig);
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if (err)
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return ERR_PTR(err);
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out:
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br_multicast_count(p->br, p, skb, igmp_type, BR_MCAST_DIR_TX);
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return p;
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}
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/* called under rcu_read_lock */
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void br_flood(struct net_bridge *br, struct sk_buff *skb,
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enum br_pkt_type pkt_type, bool local_rcv, bool local_orig)
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{
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struct net_bridge_port *prev = NULL;
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struct net_bridge_port *p;
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list_for_each_entry_rcu(p, &br->port_list, list) {
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/* Do not flood unicast traffic to ports that turn it off, nor
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* other traffic if flood off, except for traffic we originate
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*/
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switch (pkt_type) {
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case BR_PKT_UNICAST:
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if (!(p->flags & BR_FLOOD))
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continue;
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break;
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case BR_PKT_MULTICAST:
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if (!(p->flags & BR_MCAST_FLOOD) && skb->dev != br->dev)
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continue;
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break;
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case BR_PKT_BROADCAST:
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if (!(p->flags & BR_BCAST_FLOOD) && skb->dev != br->dev)
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continue;
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break;
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}
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/* Do not flood to ports that enable proxy ARP */
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if (p->flags & BR_PROXYARP)
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continue;
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if ((p->flags & (BR_PROXYARP_WIFI | BR_NEIGH_SUPPRESS)) &&
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BR_INPUT_SKB_CB(skb)->proxyarp_replied)
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continue;
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prev = maybe_deliver(prev, p, skb, local_orig);
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if (IS_ERR(prev))
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goto out;
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}
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if (!prev)
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goto out;
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if (local_rcv)
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deliver_clone(prev, skb, local_orig);
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else
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__br_forward(prev, skb, local_orig);
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return;
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out:
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if (!local_rcv)
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kfree_skb(skb);
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}
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#ifdef CONFIG_BRIDGE_IGMP_SNOOPING
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static void maybe_deliver_addr(struct net_bridge_port *p, struct sk_buff *skb,
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const unsigned char *addr, bool local_orig)
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{
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struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
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const unsigned char *src = eth_hdr(skb)->h_source;
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if (!should_deliver(p, skb))
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return;
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/* Even with hairpin, no soliloquies - prevent breaking IPv6 DAD */
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if (skb->dev == p->dev && ether_addr_equal(src, addr))
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return;
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skb = skb_copy(skb, GFP_ATOMIC);
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if (!skb) {
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dev->stats.tx_dropped++;
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return;
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}
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if (!is_broadcast_ether_addr(addr))
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memcpy(eth_hdr(skb)->h_dest, addr, ETH_ALEN);
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__br_forward(p, skb, local_orig);
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}
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/* called with rcu_read_lock */
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void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
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struct sk_buff *skb,
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struct net_bridge_mcast *brmctx,
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bool local_rcv, bool local_orig)
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{
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struct net_bridge_port *prev = NULL;
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struct net_bridge_port_group *p;
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bool allow_mode_include = true;
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struct hlist_node *rp;
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rp = br_multicast_get_first_rport_node(brmctx, skb);
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if (mdst) {
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p = rcu_dereference(mdst->ports);
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if (br_multicast_should_handle_mode(brmctx, mdst->addr.proto) &&
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br_multicast_is_star_g(&mdst->addr))
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allow_mode_include = false;
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} else {
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p = NULL;
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}
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while (p || rp) {
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struct net_bridge_port *port, *lport, *rport;
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lport = p ? p->key.port : NULL;
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rport = br_multicast_rport_from_node_skb(rp, skb);
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if ((unsigned long)lport > (unsigned long)rport) {
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port = lport;
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if (port->flags & BR_MULTICAST_TO_UNICAST) {
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maybe_deliver_addr(lport, skb, p->eth_addr,
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local_orig);
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goto delivered;
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}
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if ((!allow_mode_include &&
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p->filter_mode == MCAST_INCLUDE) ||
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(p->flags & MDB_PG_FLAGS_BLOCKED))
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goto delivered;
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} else {
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port = rport;
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}
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prev = maybe_deliver(prev, port, skb, local_orig);
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if (IS_ERR(prev))
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goto out;
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delivered:
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if ((unsigned long)lport >= (unsigned long)port)
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p = rcu_dereference(p->next);
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if ((unsigned long)rport >= (unsigned long)port)
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rp = rcu_dereference(hlist_next_rcu(rp));
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}
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if (!prev)
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goto out;
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if (local_rcv)
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deliver_clone(prev, skb, local_orig);
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else
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__br_forward(prev, skb, local_orig);
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return;
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out:
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if (!local_rcv)
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kfree_skb(skb);
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}
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#endif
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